This function allows the user to create auto-mesh on the selected surface(s). The dialog box is illustrated in Figure 5.3.5.
Figure 5.3.5 Surface Mesh dialog box
• Select a type of mesher: CONNECTED or UNCONNECTED TOOL MESH, PART MESHER, or TRIANGLE MESHER.
CONNECTED TOOL MESH will connect the adjacent surfaces if the gaps are within the surface gap tolerance (GAP TOL).
UNCONNECTED TOOL MESH will leave gaps between elements that are located on adjacent surfaces.
PART MESHER is the new topology mesher.
TRIANGLE MESHER will only generate triangle elements.
• Toggle on/off IN ORIGINAL PART. This option includes the created elements in original part or in current part.
• Toggle on/off BOUNDARY CHECK. This option checks and displays the model boundary after building the topological structures.
• Toggle on/off REFINE SHARP ANGLE. This option checks and repairs triangular element with very sharp angle (less than 5 degrees) due to bad quality of the CAD surface. The meshing speed will be reduced by 40 to 50% when this option is selected. Therefore, it should be used only when the sharp angled elements are encountered in the mesh.
• Toggle on/off RE-MESH. Once this option is selected, if the user wants to re-mesh the corresponding surface of the meshed local region, the mesh boundary is still connected to the boundary nodes in the region which is not re-meshed. Therefore, when the surface of the local region needs to be modified after all the meshes have been meshed, the user does not have to re-mesh all the meshes.
• Enter the numbers of MAXIMUM SIZE, MINIMUM SIZE, ANGLE and CHORDAL DEVIATION in the data field.
MAXIMUM SIZE
Control the maximum element size.
MINIMUM SIZE
Control the minimum element size.
ANGLE
Control the inclination of the adjacent elements.
CHORDAL DEV.
Control the number of elements at the radius.
GAP TOL
Define the allowable maximum gap between the adjacent surfaces. If the gap between adjacent surfaces is greater than gap tolerance, these two adjacent surfaces are discontinuous.
IGNORE HOLE SIZE
Ignore the holes of the surface during meshing if the hole size is less than the input criteria.
• Click SELECT SURFACES button. Refer to Section 4.4.3, PART/ADD SURFACE, for more information.
• Click APPLY to mesh the surface
If TOOL MESH is selected:
eta/DYNAFORM will create mesh suitable for punch or die definition on the selected surfaces. If the number of selected surfaces is equal to or greater than 2, the BOUNDARY CHECK is activated. The function first builds topological structures and then displays the STATUS WINDOW. See Figure 5.3.6. A message will be printed in the message prompt window.
Figure 5.3.6 Building Topological Structures
• After building the topological structures, the eta/DYNAFORM Question dialog box, as illustrated in Figure 5.3.7 is displayed. Select YES to accept the boundary and continue to the next step. Select NO to display the BOUNDARY CHECK dialog box as illustrated in Figure 5.3.8.
Figure 5.3.7 DYNAFORM Question
Figure 5.3.8 Boundary Check
Select/deselect SHOW BOUNDARY ONLY to display surfaces with model boundaries. Select OK to accept the gap tolerance. Select REDO to enter a new gap tolerance to rebuild the topological structures.
• After the user selects or accepts the gap tolerance, eta/DYNAFORM begins to mesh the surface boundaries. The status windows for meshing surface boundary and mesh generation are illustrated in Figure 5.3.9 and Figure 5.3.10, respectively.
Figure 5.3.9 Meshing Surface Boundaries
Figure 5.3.10 Creating Mesh
• The ACCEPT MESH CONFIRMATION (YES and NO) field is enabled in the SURFACE MESH dialog box. Select YES or NO to accept or reject the created mesh.
• Select OK to exit.
NOTE: When any status window appears, the user can abort the current operation by selecting ABORT.
If PART MESHER is selected:
PART MESHER is the new topology mesher used to generate part mesh for MSTEP analysis. Refer to Figure 5.3.11 for the list of control parameters.
• IN ORIGINAL PART
Mesh in original part.
• BOUNDARY CHECK
Check boundary model.
• CHECK SURFACE
Check for duplicate surfaces prior to mesh operation.
• MESH BY PART
Mesh parts one at a time. The mesh will not be connected between parts.
• AUTO REPAIR
Automatically merge gaps between elements and removes free nodes from database.
• PAVE INNER HOLE
Quadrangle elements will be meshed around the inner hole.
• REMESH
Remesh control.
• IGNORE HOLE SIZE
Fill an interior hole in the surface with mesh if the hole size is less than the input criteria.
• MESH QUALITY
Refer to Figure 5.3.12 for mesh quality control parameters.
Figure 5.3.11 Part Mesher dialog box
Figure 5.3.12 Mesh Quality dialog box
If TRIANGLE MESHER is selected:
The user can enter only the element size and the gap tolerance as shown in Figure 5.3.13.
Figure 5.3.13 Triangle Mesh dialog box